Gases that are to be shipped to various locations are generally packaged in portable vessels of various shapes and sizes which are capable of withstanding high pressures and which can be conveniently shipped. Typical of such vessels are the cylindrical containers commonly known as gas cylinders or gas bottles. These vessels are generally filled with gases by charging the gas into the vessel until the desired pressure is reached.
For many years, the process of filling cylinders with gases or gas mixtures was performed manually by an operator. The operator would distribute gases from large storage cylinders filled with liquefied gases, such as oxygen, nitrogen, argon, carbon dioxide and helium, into one or more smaller target cylinders. The operator would simultaneously fill any number of target cylinders via a manifold connected to the one or more storage cylinders. Each target cylinder was filled with the specified gas or gas mixture to a pre-determined pressure at a stated temperature.
In one conventional method of creating a gas mixture, the various component gases distributed into the target cylinder are successively weighed to obtain the desired gas ratios. In performing these various steps, the operator would continuously monitor the weight of the cylinders, the temperature of the cylinders and the pressures in the system. The entire process was very time consuming and resulted in lost time for the operator and the equipment.
In view of the foregoing, it would be advantageous to further develop and refine systems for filling cylinders with gas in the interests of convenience and reduced operating costs.